254 research outputs found
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System study of a diode-pumped solid-state-laser driver for inertial fusion energy
The present a conceptual design of a diode-pumped solid-state-laser (DPSSL) driver for an inertial fusion energy (IFE) power plant based on the maximized cost of electricity (COE) as determined in a comprehensive systems study. This study contained extensive detail for all significant DPSSL physics and costs, plus published scaling relationships for the costs of the target chamber and the balance of plant (BOP). Our DPSSL design offers low development cost because it is modular, can be fully tested functionally at reduced scale, and is based on mature solid-state-laser technology. Most of the parameter values that we used are being verified by experiments now in progress. Future experiments will address the few issues that remain. As a consequence, the economic and technical risk of our DPSSL driver concept is becoming rather low. Baseline performance at 1 GW{sub e} using a new gain medium [Yb{sup 3+}-doped Sr{sub 5}(PO{sub 4}){sub 3}F or Yb:S-FAP] includes a product of laser efficiency and target gain of {eta}G = 7, and a COE of 8.6 cents/kW{center_dot}h, although values of {eta}G {ge} 11 and COEs {le}6.6 cents/kW{center_dot}h are possible at double the assumed target gain of 76 at 3.7 MJ. We present a summary of our results, discuss why other more-common types of laser media do not perform as well as Yb:S-FAP, and present a simple model that shows where DPSSL development should proceed to reduce projected COEs
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Penetrating radiation impact on NIF final optic components
Goal of the National Ignition Facility (NIF) is to achieve thermonuclear ignition in a laboratory environment in inertial confinement fusion (ICF). This will enable NIF to service the DOE stockpile stewardship management program, inertial fusion energy goals, and advance scientific frontiers. All of these applications will make use of the extreme conditions that the facility will create in the target chamber. In the case of a prospected 20 MJ yield scenario, NIF will produce 10{sup 19} neutrons with DT fusion 14 MeV energy per neutron. There will also be high-energy x rays as well as solid, liquid, and gaseous target debris produced either directly or indirectly by the inertial confinement fusion process. A critical design issue is the protection of the final optical components as well as sophisticated target diagnostics in such a harsh environment
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Neutron and gamma irradiated optical property changes for the final optics of the National Ignition Facility
Based on studies the authors have performed with several radiation sources such as pulsed nuclear reactors, they have been able to construct a physical picture and measure quantitative parameters necessary to model the radiation-induced losses expected for fused silica and fused quartz National Ignition Facility (NIF) target area. It is important to note that these surrogate radiation sources do not have identical temporal and spectral characteristics to NIF, therefore caution is in order since the results obtained to date must be extrapolated somewhat to predict NIF performance
First Experimental Demonstration of Full-Duplex Optical Communications on a Single Laser Beam
We present the results of the first experimental demonstration a novel communications architecture that will be deployed on a Space Shuttle mission in 2003. This architecture can provide a very lightweight, low power consumption, low data rate communications link between the earth and LEO satellites. A unique characteristic of this system is that it provides full-duplex communications on a single beam is presented. The results of first experiments demonstrating this full duplex communications architecture are presented
Ixekizumab Citrate-Free Formulation : Results from Two Clinical Trials
Introduction: Subcutaneous (SC) injection is a common route of drug administration; however, injection site pain (ISP) might create a negative patient experience. We evaluated ISP, bioequivalence, and overall safety of the citrate-free (CF) formulation of ixekizumab, a high-affinity monoclonal antibody that selectively targets interleukin-17A. Methods: Two phase 1, single-blind studies were conducted in healthy participants. The crossover study A (NCT03848403) evaluated pain intensity on injection as measured by visual analog scale of pain (VAS) scores. Subjects (N = 70) were randomized 1:1:1 at the beginning to three possible treatment sequences and received a 1 mL SC injection of the three formulations sequentially in the abdomen on days 1, 8, and 15, respectively. A mixed-effects repeated measures analysis model was used to analyze VAS score by time post-injection. Study B (NCT04259346) evaluated the bioequivalence of a single 80 mg dose of CF formulation compared to the original commercial formulation. Subjects (N = 245) were randomized 1:1 to either commercial or CF formulation and received a single SC injection into the abdomen, arm, or thigh. Results: Primary endpoint was achieved in both studies. In study A, least-squares mean (LSM) difference of VAS scores immediately post injection between commercial (n = 61) and CF formulation (n = 63) was − 21.7 (p < 0.0001), indicating a lower degree of pain associated with CF formulation. In study B, bioequivalence of the CF formulation was established as 90% CIs for the ratio of geometric LSM AUC, AUC, and C between treatments were contained within the prespecified limits of 0.8 and 1.25. Except for less ISP in the CF formulation, overall safety profile was comparable. Conclusion: Ixekizumab CF formulation proved to be bioequivalent, was associated with less ISP, and had no other notable differences in the safety profile compared to the original commercial formulation. Trail Registration: ClinicalTrials.gov identifier NCT03848403, NCT04259346
Lightweight Optical Wavelength Communications without a Laser in Space
We will present a model for an earth-to-low-earthorbit optical communications system. The system modeled herein is designed to offer a very lightweight, low power consumption, low data rate communications link from LEO satellites. A novel architecture for a free-space optical communications link is presented and analyzed. For the first time, a method that offers full-duplex communications on a single beam is presented. In addition, a novel data format for free-space optical communications is presented. In this system, both the laser and the downlink receiver are located on the ground. The optical elements located on the spacecraft are a simple uplink receiver and a retromodulator. In fact, the laser transmitter for the system is a semiconductor device. We will present a simple feasibility model for the LOWCAL experiment that provides an estimate of the performance capability and identifies major system tradeoffs. Assuming a laser transmitter power of - 7-dB and a communications data rate of 10-kbps, we expect link margins of 17 dB for the downlink. For the uplink, an SC-FSK format is proposed that is invisible to the downlink and provides a link margin of 20 dB
Managing for nitrogen, the lesser of two evils. A response to Maes et al.
Letter to the Editor
New cytochrome P450 1B1, 1C2 and 1D1 genes in the killifish Fundulus heteroclitus : Basal expression and response of five killifish CYP1s to the AHR agonist PCB126
Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Aquatic Toxicology 93 (2009): 234-243, doi:10.1016/j.aquatox.2009.05.008.Knowledge of the complement of cytochrome P450 (CYP) genes is essential to understanding
detoxification and bioactivation mechanisms for organic contaminants.We cloned three new
CYP1 genes, CYP1B1, CYP1C2 and CYP1D1, from the killifish Fundulus heteroclitus, an
important model in environmental toxicology. Expression of the new CYP1s along with
previously known CYP1A and CYP1C1 was measured by qPCR in eight different organs. Organ
distribution was similar for the two CYP1Cs, but otherwise patterns and extent of expression
differed among the genes. The AHR agonist 3,3_,4,4_,5-pentachlorobiphenyl (PCB126) (31
pmol/g fish) induced expression of CYP1A and CYP1B1 in all organs examined, while CYP1C1
was induced in all organs except testis. The largest changes in response to PCB126 were
induction of CYP1A in testis (~700-fold) and induction of CYP1C1 in liver (~500-fold). CYP1B1
in liver and gut, CYP1A in brain and CYP1C1 in gill also were induced strongly by PCB126
(>100-fold). CYP1C1 expression levels were higher than CYP1C2 in almost all tissues and
CYP1C2 was much less responsive to PCB126. In contrast to the other genes, CYP1D1 was not
induced by PCB126 in any of the organs. The organ-specific response of CYP1s to PCB126
implies differential involvement in effects of halogenated aromatic hydrocarbons in different
organs. The suite of inducible CYP1s could enhance the use of F. heteroclitus in assessing
aquatic contamination by AHR agonists. Determining basal and induced levels of protein and the
substrate specificity for all five CYP1s will be necessary to better understand their roles in
chemical effects and physiology.This study was supported in part by NIH grants JJS (the Superfund Basic Research Program
5P42ES007381 and R01ES015912) and MJJ (K99ES017044-01)
Production and Decay of D_1(2420)^0 and D_2^*(2460)^0
We have investigated and final states and
observed the two established charmed mesons, the with mass
MeV/c and width MeV/c and
the with mass MeV/c and width
MeV/c. Properties of these final states, including
their decay angular distributions and spin-parity assignments, have been
studied. We identify these two mesons as the doublet predicted
by HQET. We also obtain constraints on {\footnotesize } as a function of the cosine of the relative phase of the two
amplitudes in the decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by
sending mail to: [email protected]
Measurement of the branching fraction for
We have studied the leptonic decay of the resonance into tau
pairs using the CLEO II detector. A clean sample of tau pair events is
identified via events containing two charged particles where exactly one of the
particles is an identified electron. We find . The result is consistent with
expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS
94/1297, CLEO 94-20 (submitted to Physics Letters B
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